N-ros is one of the transforming genes in human hepatic cancer cells. It has been found that N-ras was overexpressed at the mENA and protein level in hepatoma cells. In order to explore the biological roles of N-ras i...N-ros is one of the transforming genes in human hepatic cancer cells. It has been found that N-ras was overexpressed at the mENA and protein level in hepatoma cells. In order to explore the biological roles of N-ras in human hepatic oaroinogenesis and the potential application in control of cancer cell growth, a pseudotype retrovirus containing antisense sequence of human N-ras was constructed and packaged. A recombinant rebrovirus vector containing antisense or sense sequences of N-ras oDNA was constructed by pZIP-NeoSV(X)1. The pseudotype virus was packaged and rescued by transfeotion and infection in PA317 and ψ2 helper cells. It has been demonstrated that the pseudotype retrovirus containing antisense N-ras sequence did inhibit the growth of human PLC/PEF/5 hepatoma cells accompanied with inhibition of p21 expression, while the retrovirus containing sense sequence had none. The pseudotype virus had no effect on human diploid fibroblasts.展开更多
Electrochemical and corrosion behaviour of reinforced steel embedded in cement pastes incorporating different amounts of silica fume as a partial replacement of cement has been studied in chloride and sulphate solutio...Electrochemical and corrosion behaviour of reinforced steel embedded in cement pastes incorporating different amounts of silica fume as a partial replacement of cement has been studied in chloride and sulphate solutions by using different electrochemical techniques. The results indicate that, while steel passivity degree is low in the control samples' upon soaking in the corrosive media, it has been high in samples incorporating silica fume and increased with increasing silica fume content. The improvement effect of silica fume may be attributed to the pore solution structure of the cement paste, which limits the mobility of aggressive ions near the surface of the steel. The mechanism of steel corrosion due to chloride and sulphate attack and passivation effect of silica fume are discussed.展开更多
This study describes the use of algae as potential bioindicators of pollution containing industrial metals. Phytoplanktonic algae varied with waste type and with environmental and growth conditions.In water samples co...This study describes the use of algae as potential bioindicators of pollution containing industrial metals. Phytoplanktonic algae varied with waste type and with environmental and growth conditions.In water samples containing cermic waste Euglenophyta species and Cyclotella sp. (Bacillariophyta) were determined as potential indicator species of pollution, while in sample containing metallic waste, Cyclolella sp. was most dominant. Under laboratory growth conditions, phytoplankton collected from a major stream of the Nile River were cultivated by using Algal Growth Bottle Test (EPA, 1972). This revealed that Scensdesmus sp., Actinastrum hantzschii (Chlorophyta), Oscillatoria limneica (Cyanophyta) and Nitzschia linearis (Bacilldriophyta) were also poential indicators of pollution.展开更多
文摘N-ros is one of the transforming genes in human hepatic cancer cells. It has been found that N-ras was overexpressed at the mENA and protein level in hepatoma cells. In order to explore the biological roles of N-ras in human hepatic oaroinogenesis and the potential application in control of cancer cell growth, a pseudotype retrovirus containing antisense sequence of human N-ras was constructed and packaged. A recombinant rebrovirus vector containing antisense or sense sequences of N-ras oDNA was constructed by pZIP-NeoSV(X)1. The pseudotype virus was packaged and rescued by transfeotion and infection in PA317 and ψ2 helper cells. It has been demonstrated that the pseudotype retrovirus containing antisense N-ras sequence did inhibit the growth of human PLC/PEF/5 hepatoma cells accompanied with inhibition of p21 expression, while the retrovirus containing sense sequence had none. The pseudotype virus had no effect on human diploid fibroblasts.
文摘Electrochemical and corrosion behaviour of reinforced steel embedded in cement pastes incorporating different amounts of silica fume as a partial replacement of cement has been studied in chloride and sulphate solutions by using different electrochemical techniques. The results indicate that, while steel passivity degree is low in the control samples' upon soaking in the corrosive media, it has been high in samples incorporating silica fume and increased with increasing silica fume content. The improvement effect of silica fume may be attributed to the pore solution structure of the cement paste, which limits the mobility of aggressive ions near the surface of the steel. The mechanism of steel corrosion due to chloride and sulphate attack and passivation effect of silica fume are discussed.
文摘This study describes the use of algae as potential bioindicators of pollution containing industrial metals. Phytoplanktonic algae varied with waste type and with environmental and growth conditions.In water samples containing cermic waste Euglenophyta species and Cyclotella sp. (Bacillariophyta) were determined as potential indicator species of pollution, while in sample containing metallic waste, Cyclolella sp. was most dominant. Under laboratory growth conditions, phytoplankton collected from a major stream of the Nile River were cultivated by using Algal Growth Bottle Test (EPA, 1972). This revealed that Scensdesmus sp., Actinastrum hantzschii (Chlorophyta), Oscillatoria limneica (Cyanophyta) and Nitzschia linearis (Bacilldriophyta) were also poential indicators of pollution.
